Method and apparatus for forming nano-particles

Abstract

Nano-scale particles of materials can be produced by vaporizing the material and allowing the material to flow in a non-violently turbulent manner into thermal communication with a cooling fluid, thereby forming small particles of the material that can be in the nano-scale size range.

Description

PRIORITY INFORMATION[0001]This application is based on and claims priority to U.S. Provisional Application No. 60 / 529,724, filed Dec. 15, 2003, and U.S. Provisional Application No. 60 / 568,457, filed May 4, 2004, the entire contents of both of which is hereby expressly incorporated by reference.BACKGROUND OF THE INVENTIONS[0002]1. Field of the Inventions[0003]The inventions disclosed herein relate to the production of nano-sized particles. In particular, the inventions relate to the vaporization and condensation of material for forming nano-sized particles of the material.[0004]2. Description of the Related Art[0005]Techniques for producing nanoparticles generally fall into one of three categories, namely: mechanical, chemical or thermal processing. In mechanical processes, nanopowders are commonly made by crushing techniques such as ball milling. There are several disadvantages to this approach. The grinding media and the mill wear away and combine with the nanomaterial, contaminati...

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Benefits of technology

[0009]An aspect of at least one of the inventions disclosed herein includes the realization that significant improvements in particle size distribution can be achieved by reducing turbulence in the flows of vaporized material and cooling gas. For example, in a thermal-type process for forming nano-scale particles, a reduction in the turbulence of the flow of vaporized material and / or cooling gas allows the vaporized particles to be quenched in a more uniform manner, thereby resulting in better (e.g., narrower) particle size distribution.

Problems solved by technology

There are several disadvantages to this approach.

The grinding media and the mill wear away and combine with the nanomaterial, contaminating the final product.

Additionally, nanoparticles produced by ball milling tend to be non-uniform in size and shape and have a wide distribution of particle sizes.

Such methods can produce powders contaminated by unreacted materials such as carbon.

Ion collision and electron beam evaporation tend to be too slow for commercial processes.

Laser ablation has the disadvantage of being extremely expensive due to an inherent energy inefficiency.

This process produces particles with a large size distribution, uses large quantities of gas, and is difficult to scale to commercial bulk production.

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